THE ROLE OF MUCILAGE IN THE GERMINATION OF CUIPO,CAVANILLESIA PLATANIFOLIA (H. & B.) H. B. K. (BOMBACACEAE), A TROPICAL TREE

The mucilage in the fruits of cuipo, Cavanillesia platanifolia, is an adaptation to the unpredictable rainfall at the beginning of the rainy season in the tropical moist forests of central Panama. It allows cuipo to germinate rapidly following rains in the early rainy season, before other potential competitors. Mucilage comprises ~27% of the mass of the large (~3.5 g) wind-dispersed fruits of cuipo. Water uptake capacity of cuipo fruits (7 g water/g fruit in 10 min) was greater than that of the diaspores of five wind-dispersed species sympatric with cuipo. Diaspores of these five species lost all their absorbed water within 2 days but cuipo retained it for 2 wk. Experiments using two mucilage treatments (seeds within fruit and seeds alone) and three watering treatments (daily, weekly, and biweekly) indicated that 1) neither mucilage nor watering treatments altered percent germination; 2) the presence of mucilage-rich fruits lessened the effects of drought on seedling development and decreased the degree of wilting; and 3) both treatments interacted in their effects on percent and cause of mortality.